Longitudinal position (“LP”) information in a recording tape assists a tape drive control system to quickly and reliably transport tape to a desired longitudinal position along a length of the tape. This condition may reduce an amount of time a user is required to wait for the tape drive to either retrieve data or to write new data in a pre-designated clear area of the tape. In magnetic tape drives, the LP information is embedded in the tape itself where this LP information is written magnetically during a servo track writing process performed during the manufacturing of the tape cartridge.
One implementation as set forth in U.S. Pat. No. 7,646,694 (“the '694 patent) to Monen et al. provides a method and a system for providing data track identifying information on a recording medium.
For example, the '694 patent provides a method for providing identifying information for a data track in an optical tape. The method comprises transporting the optical tape in a longitudinal direction and scanning at least one laser beam in another direction that is substantially transverse to the longitudinal direction. The method further comprises selecting size and position of a plurality of spaced recording locations in order to obtain a distinguishable pattern of the spaced recording locations and recording a plurality of servomarks at a majority of locations from the plurality of spaced recording locations, each servomark from the plurality of servomarks being substantially located on a data track. The method further comprises omitting recording at preselected locations from the plurality of spaced recording locations and returning the at least one laser beam back to a position substantially on the longitudinal direction. The method further comprises repeating various steps noted above to form all servomarks from the plurality of servomarks in one pass of the optical tape from substantially a beginning of the optical tape to substantially an end of the optical tape; where the preselected locations constitute a pattern providing the identifying information.